Evalbot nunchuck control

[Martin] got his evalbot recently and wanted to try controlling it with his Wii nunchuck. After some trial and error, he finally got it working. He’s shown that controlling the bot with the nunchuck was actually pretty simple, but there are some other tips that could be pretty helpful in the process. One was the fact that the point where he’s taking power for the nunchuck could easily be shorted on the motor. He wrapped his in tape, but we could see this little bug pestering us for a while before we figured out what it was. You can download his code and see his build process on his site. Be sure to catch the video of it working in both accelerometer and joystick mode after the break.

“Due to plating tolerances, it might be difficult to fit the wheels to the motor shaft if the wheel is assembled first. Instead, fit all three wheel pieces to the motor shaft before inserting the set-screws.”

The 3 pieces of each wheel went onto the axles fine here. I need to get some clamps though to redo them as there is a gap between the pieces. Its hard to get them completely flush when putting in the grub screws.

Samtec.com will send out samples of the connector needed for the EM ports. It’s part number SFM-110-02-S-D
I’m using these to breakout the SPI and I2C buses to a breadboard. Used hardboard, nylon spacers and 4-40 screws to build a platform 3/4″ above the robot.

Massive thanks to Martin for posting the source and his Eclipse project files — I was able to compile this code locally and get my evalbot OLED screen to say hello. The display code seems buggy (screen shows random junk) when writing more than one line out to the display, but I’m not one to complain!

I had to piece details from various places to get the toolchain (use CodeSourcery G++ lite) and openocd up and running — If time permits and/or I can refine the firmware flash process with openocd (e.g. automate it) then I’ll write up a tutorial for your pleasure and/or disdain. I recommend you start by creating a virtual machine (OpenBox, not the OSE version though!) and install Ubuntu to isolate the tools from your daily environment.

hi.i need some help with the evalbot. i want to find the ports where i can send some signals and see the response on osciloscope.i see there is some ports PJ2,3,4… but i’m not sure.can someone help me with this?